Method for exchanging heat in vapor compression heat transfer systems

ABSTRACT

A multi-step method is disclosed for exchanging heat in a vapor compression heat transfer system having a working fluid circulating therethrough. The method includes the step of circulating a working fluid comprising a fluoroolefin to an inlet of a first tube of an internal heat exchanger, through the internal heat exchanger and to an outlet thereof. Also disclosed are vapor compression heat transfer systems for exchanging heat. The systems include an evaporator, a compressor, a dual-row condenser and an intermediate heat exchanger having a first tube and a second tube. A disclosed system involves a dual-row condenser connected to the first and second intermediate heat exchanger tubes. Another disclosed system involves a dual-row evaporator connected to the first and second intermediate heat exchanger tubes.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of and claims the prioritybenefit of pending U.S. patent application Ser. No. 12/119,023, filedMay 12, 2008, which claims the priority benefit of U.S. ProvisionalApplication No. 60/928,826, filed May 11, 2007, U.S. ProvisionalApplication No. 60/988,562, filed Nov. 16, 2007 and PCT Application No.U.S. 07/25675, filed Dec. 17, 2007.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a method for exchanging heat in avapor compression heat transfer system. In particular, it relates to useof an intermediate heat exchanger to improve performance of a vaporcompression heat transfer system utilizing a working fluid comprising atleast one fluoroolefin.

2. Description of Related Art

Methods for improving the performance of heat transfer systems, such asrefrigeration systems and air conditioners, are always being sought, inorder to reduce cost of operation of such systems.

When new working fluids for heat transfer systems, including vaporcompression heat transfer systems, are being proposed it is important tobe able to provide means of improving cooling capacity and energyefficiency for the new working fluids.

SUMMARY OF THE INVENTION

Applicants have found that the use of an internal heat exchanger in avapor compression heat transfer system that uses a fluoroolefin providesunexpected benefits due to sub-cooling of the working fluid exiting outof the condenser. By “subcooling” is meant the reduction of thetemperature of a liquid below that liquid's saturation point for a givenpressure. The saturation point is the temperature at which the vaporusually would condense to a liquid, but subcooling produces a lowertemperature vapor at the given pressure. By cooling a vapor below thesaturation point, the net refrigeration capacity can be increased.Sub-cooling thereby improves cooling capacity and energy efficiency of asystem, such as vapor compression heat transfer systems, which comprisefluoroolefins.

In particular, when the fluoroolefin 2,3,3,3-tetrafluoropropene(HFC-1234yf) is used as the working fluid, surprising results have beenachieved with respect to coefficient of performance and capacity of theworking fluid, as compared to the use of known working fluids such as1,1,1,2-tetrafluoroethane (HFC-124a).

Therefore, in accordance with the present invention, the presentdisclosure provides a method of exchanging heat in a vapor compressionheat transfer system, comprising:

-   -   (a) circulating a working fluid comprising a fluoroolefin to an        inlet of a first tube of an internal heat exchanger, through the        internal heat exchanger and to an outlet thereof;    -   (b) circulating the working fluid from the outlet of the first        tube of the internal heat exchanger to an inlet of an        evaporator, through the evaporator to evaporate the working        fluid into a gas, and through an outlet of the evaporator;    -   (c) circulating the working fluid from the outlet of the        evaporator to an inlet of a second tube of the internal heat        exchanger to transfer heat from the liquid working fluid from        the condenser to the gaseous working fluid from the evaporator,        through the internal heat exchanger, and to an outlet of the        second tube;    -   (d) circulating the working fluid from the outlet of the second        tube of the internal heat exchanger to an inlet of a compressor,        through the compressor to compress the working fluid gas, and to        an outlet of the compressor;    -   (e) circulating the working fluid from the outlet of the        compressor to an inlet of a condenser and through the condenser        to condense the compressed working fluid gas into a liquid, and        to an outlet of the condenser;    -   (f) circulating the working fluid from the outlet of the        condenser to an inlet of the first tube of the intermediate heat        exchanger to transfer heat from the liquid from the condenser to        the gas from the evaporator, and to an outlet of the second        tube; and    -   (g) circulating the working fluid from the outlet of the second        tube of the internal heat exchanger back to the evaporator.

The fluorolefin is a compound selected from the group consisting of:

-   -   (i) fluoroolefins of the formula E- or Z—R¹CH═CHR², wherein R¹        and R² are, independently, C₁ to C₆ perfluoroalkyl groups;    -   (ii) cyclic fluoroolefins of the formula        cyclo-[CX═CY(CZW)_(n)—], wherein X, Y, Z, and W, independently,        are H or F, and n is an integer from 2 to 5; and    -   (iii) fluoroolefins selected from the group consisting of:        1,2,3,3,3-pentafluoro-1-propene (CHF═CFCF₃),        1,1,3,3,3-pentafluoro-1-propene (CF₂═CHCF₃),        1,1,2,3,3-pentafluoro-1-propene (CF₂═CFCHF₂),        1,2,3,3-tetrafluoro-1-propene (CHF═CFCHF₂),        2,3,3,3-tetrafluoro-1-propene (CH₂═CFCF₃),        1,3,3,3-tetrafluoro-1-propene (CHF═CHCF₃),        1,1,2,3-tetrafluoro-1-propene (CF₂═CFCH₂F),        1,1,3,3-tetrafluoro-1-propene (CF₂═CHCHF₂),        1,2,3,3-tetrafluoro-1-propene (CHF═CFCHF₂),        3,3,3-trifluoro-1-propene (CH₂═CHCF₃), 2,3,3-trifluoro-1-propene        (CHF₂CF═CH₂); 1,1,2-trifluoro-1-propene (CH₃CF═CF₂);        1,2,3-trifluoro-1-propene (CH₂FCF═CF₂);        1,1,3-trifluoro-1-propene (CH₂FCH═CF₂);        1,3,3-trifluoro-1-propene (CHF₂CH═CHF);        1,1,1,2,3,4,4,4-octafluoro-2-butene (CF₃CF═CFCF₃);        1,1,2,3,3,4,4,4-octafluoro-1-butene (CF₃CF₂CF═CF₂);        1,1,1,2,4,4,4-heptafluoro-2-butene (CF₃CF═CHCF₃);        1,2,3,3,4,4,4-heptafluoro-1-butene (CHF═CFCF₂CF₃);        1,1,1,2,3,4,4-heptafluoro-2-butene (CHF₂CF═CFCF₃);        1,3,3,3-tetrafluoro-2-(trifluoromethyl)-1-propene ((CF₃)₂C═CHF);        1,1,3,3,4,4,4-heptafluoro-1-butene (CF₂═CHCF₂CF₃);        1,1,2,3,4,4,4-heptafluoro-1-butene (CF₂═CFCHFCF₃);        1,1,2,3,3,4,4-heptafluoro-1-butene (CF₂═CFCF₂CHF₂);        2,3,3,4,4,4-hexafluoro-1-butene (CF₃CF₂CF═CH₂);        1,3,3,4,4,4-hexafluoro-1-butene (CHF═CHCF₂CF₃);        1,2,3,4,4,4-hexafluoro-1-butene (CHF═CFCHFCF₃);        1,2,3,3,4,4-hexafluoro-1-butene (CHF═CFCF₂CHF₂);        1,1,2,3,4,4-hexafluoro-2-butene (CHF₂CF═CFCHF₂);        1,1,1,2,3,4-hexafluoro-2-butene (CH₂FCF═CFCF₃);        1,1,1,2,4,4-hexafluoro-2-butene (CHF₂CH═CFCF₃);        1,1,1,3,4,4-hexafluoro-2-butene (CF₃CH═CFCHF₂);        1,1,2,3,3,4-hexafluoro-1-butene (CF₂═CFCF₂CH₂F);        1,1,2,3,4,4-hexafluoro-1-butene (CF₂═CFCHFCHF₂);        3,3,3-trifluoro-2-(trifluoromethyl)-1-propene (CH₂═C(CF₃)₂);        1,1,1,2,4-pentafluoro-2-butene (CH₂FCH═CFCF₃);        1,1,1,3,4-pentafluoro-2-butene (CF₃CH═CFCH₂F);        3,3,4,4,4-pentafluoro-1-butene (CF₃CF₂CH═CH₂);        1,1,1,4,4-pentafluoro-2-butene (CHF₂CH═CHCF₃);        1,1,1,2,3-pentafluoro-2-butene (CH₃CF═CFCF₃);        2,3,3,4,4-pentafluoro-1-butene (CH₂═CFCF₂CHF₂);        1,1,2,4,4-pentafluoro-2-butene (CHF₂CF═CHCHF₂);        1,1,2,3,3-pentafluoro-1-butene (CH₃CF₂CF═CF₂);        1,1,2,3,4-pentafluoro-2-butene (CH₂FCF═CFCHF₂);        1,1,3,3,3-pentafluoro-2-methyl-1-propene (CF₂═C(CF₃)(CH₃));        2-(difluoromethyl)-3,3,3-trifluoro-1-propene (CH₂═C(CHF₂)(CF₃));        2,3,4,4,4-pentafluoro-1-butene (CH₂═CFCHFCF₃);        1,2,4,4,4-pentafluoro-1-butene (CHF═CFCH₂CF₃);        1,3,4,4,4-pentafluoro-1-butene (CHF═CHCHFCF₃);        1,3,3,4,4-pentafluoro-1-butene (CHF═CHCF₂CHF₂);        1,2,3,4,4-pentafluoro-1-butene (CHF═CFCHFCHF₂);        3,3,4,4-tetrafluoro-1-butene (CH₂═CHCF₂CHF₂);        1,1-difluoro-2-(difluoromethyl)-1-propene (CF₂═C(CHF₂)(CH₃));        1,3,3,3-tetrafluoro-2-methyl-1-propene (CHF═C(CF₃)(CH₃));        3,3-difluoro-2-(difluoromethyl)-1-propene (CH₂═C(CHF₂)₂);        1,1,1,2-tetrafluoro-2-butene (CF₃CF═CHCH₃);        1,1,1,3-tetrafluoro-2-butene (CH₃CF═CHCF₃);        1,1,1,2,3,4,4,5,5,5-decafluoro-2-pentene (CF₃CF═CFCF₂CF₃);        1,1,2,3,3,4,4,5,5,5-decafluoro-1-pentene (CF₂═CFCF₂CF₂CF₃);        1,1,1,4,4,4-hexafluoro-2-(trifluoromethyl)-2-butene        ((CF₃)₂C═CHCF₃); 1,1,1,2,4,4,5,5,5-nonafluoro-2-pentene        (CF₃CF═CHCF₂CF₃); 1,1,1,3,4,4,5,5,5-nonafluoro-2-pentene        (CF₃CH═CFCF₂CF₃); 1,2,3,3,4,4,5,5,5-nonafluoro-1-pentene        (CHF═CFCF₂CF₂CF₃); 1,1,3,3,4,4,5,5,5-nonafluoro-1-pentene        (CF₂═CHCF₂CF₂CF₃); 1,1,2,3,3,4,4,5,5-nonafluoro-1-pentene        (CF₂═CFCF₂CF₂CHF₂); 1,1,2,3,4,4,5,5,5-nonafluoro-2-pentene        (CHF₂CF═CFCF₂CF₃); 1,1,1,2,3,4,4,5,5-nonafluoro-2-pentene        (CF₃CF═CFCF₂CHF₂); 1,1,1,2,3,4,5,5,5-nonafluoro-2-pentene        (CF₃CF═CFCHFCF₃);        1,2,3,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene        (CHF═CFCF(CF₃)₂);        1,1,2,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene        (CF₂═CFCH(CF₃)₂);        1,1,1,4,4,4-hexafluoro-2-(trifluoromethyl)-2-butene        (CF₃CH═C(CF₃)₂);        1,1,3,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene        (CF₂═CHCF(CF₃)₂); 2,3,3,4,4,5,5,5-octafluoro-1-pentene        (CH₂═CFCF₂CF₂CF₃); 1,2,3,3,4,4,5,5-octafluoro-1-pentene        (CHF═CFCF₂CF₂CHF₂);        3,3,4,4,4-pentafluoro-2-(trifluoromethyl)-1-butene        (CH₂═C(CF₃)CF₂CF₃);        1,1,4,4,4-pentafluoro-3-(trifluoromethyl)-1-butene        (CF₂═CHCH(CF₃)₂);        1,3,4,4,4-pentafluoro-3-(trifluoromethyl)-1-butene        (CHF═CHCF(CF₃)₂);        1,1,4,4,4-pentafluoro-2-(trifluoromethyl)-1-butene        (CF₂═C(CF₃)CH₂CF₃);        3,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene        ((CF₃)₂CFCH═CH₂); 3,3,4,4,5,5,5-heptafluoro-1-pentene        (CF₃CF₂CF₂CH═CH₂); 2,3,3,4,4,5,5-heptafluoro-1-pentene        (CH₂═CFCF₂CF₂CHF₂); 1,1,3,3,5,5,5-heptafluoro-1-butene        (CF₂═CHCF₂CH₂CF₃); 1,1,1,2,4,4,4-heptafluoro-3-methyl-2-butene        (CF₃CF═C(CF₃)(CH₃));        2,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene        (CH₂═CFCH(CF₃)₂);        1,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene        (CHF═CHCH(CF₃)₂);        1,1,1,4-tetrafluoro-2-(trifluoromethyl)-2-butene        (CH₂FCH═C(CF₃)₂);        1,1,1,3-tetrafluoro-2-(trifluoromethyl)-2-butene        (CH₃CF═C(CF₃)₂); 1,1,1-trifluoro-2-(trifluoromethyl)-2-butene        ((CF₃)₂C═CHCH₃); 3,4,4,5,5,5-hexafluoro-2-pentene        (CF₃CF₂CF═CHCH₃); 1,1,1,4,4,4-hexafluoro-2-methyl-2-butene        (CF₃C(CH₃)═CHCF₃); 3,3,4,5,5,5-hexafluoro-1-pentene        (CH₂═CHCF₂CHFCF₃); 4,4,4-trifluoro-2-(trifluoromethyl)-1-butene        (CH₂═C(CF₃)CH₂CF₃);        1,1,2,3,3,4,4,5,5,6,6,6-dodecafluoro-1-hexene (CF₃(CF₂)₃CF═CF₂);        1,1,1,2,2,3,4,5,5,6,6,6-dodecafluoro-3-hexene        (CF₃CF₂CF═CFCF₂CF₃);        1,1,1,4,4,4-hexafluoro-2,3-bis(trifluoromethyl)-2-butene        ((CF₃)₂C═C(CF₃)₂);        1,1,1,2,3,4,5,5,5-nonafluoro-4-(trifluoromethyl)-2-pentene        ((CF₃)₂CFCF═CFCF₃);        1,1,1,4,4,5,5,5-octafluoro-2-(trifluoromethyl)-2-pentene        ((CF₃)₂C═CHC₂F₅);        1,1,1,3,4,5,5,5-octafluoro-4-(trifluoromethyl)-2-pentene        ((CF₃)₂CFCF═CHCF₃); 3,3,4,4,5,5,6,6,6-nonafluoro-1-hexene        (CF₃CF₂CF₂CF₂CH═CH₂);        4,4,4-trifluoro-3,3-bis(trifluoromethyl)-1-butene        (CH₂═CHC(CF₃)₃);        1,1,1,4,4,4-hexafluoro-3-methyl-2-(trifluoromethyl)-2-butene        ((CF₃)₂C═C(CH₃)(CF₃));        2,3,3,5,5,5-hexafluoro-4-(trifluoromethyl)-1-pentene        (CH₂═CFCF₂CH(CF₃)₂);        1,1,1,2,4,4,5,5,5-nonafluoro-3-methyl-2-pentene        (CF₃CF═C(CH₃)CF₂CF₃);        1,1,1,5,5,5-hexafluoro-4-(trifluoromethyl)-2-pentene        (CF₃CH═CHCH(CF₃)₂); 3,4,4,5,5,6,6,6-octafluoro-2-hexene        (CF₃CF₂CF₂CF═CHCH₃); 3,3,4,4,5,5,6,6-octafluoro1-hexene        (CH₂═CHCF₂CF₂CF₂CHF₂);        1,1,1,4,4-pentafluoro-2-(trifluoromethyl)-2-pentene        ((CF₃)₂C═CHCF₂CH₃);        4,4,5,5,5-pentafluoro-2-(trifluoromethyl)-1-pentene        (CH₂═C(CF₃)CH₂C₂F₅);        3,3,4,4,5,5,5-heptafluoro-2-methyl-1-pentene        (CF₃CF₂CF₂C(CH₃)═CH₂); 4,4,5,5,6,6,6-heptafluoro-2-hexene        (CF₃CF₂CF₂CH═CHCH₃); 4,4,5,5,6,6,6-heptafluoro-1-hexene        (CH₂═CHCH₂CF₂C₂F₅); 1,1,1,2,2,3,4-heptafluoro-3-hexene        (CF₃CF₂CF═CFC₂H₅);        4,5,5,5-tetrafluoro-4-(trifluoromethyl)-1-pentene        (CH₂═CHCH₂CF(CF₃)₂);        1,1,1,2,5,5,5-heptafluoro-4-methyl-2-pentene        (CF₃CF═CHCH(CF₃)(CH₃));        1,1,1,3-tetrafluoro-2-(trifluoromethyl)-2-pentene        ((CF₃)₂C═CFC₂H₅);        1,1,1,2,3,4,4,5,5,6,6,7,7,7-tetradecafluoro-2-heptene        (CF₃CF═CCF₂CF₂C₂F₅);        1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene        (CF₃CF₂CF═CFCF₂C₂F₅);        1,1,1,3,4,4,5,5,6,6,7,7,7-tridecafluoro-2-heptene        (CF₃CH═CFCF₂CF₂C₂F₅);        1,1,1,2,4,4,5,5,6,6,7,7,7-tridecafluoro-2-heptene        (CF₃CF═CHCF₂CF₂C₂F₅);        1,1,1,2,2,4,5,5,6,6,7,7,7-tridecafluoro-3-heptene        (CF₃CF₂CH═CFCF₂C₂F₅);        1,1,1,2,2,3,5,5,6,6,7,7,7-tridecafluoro-3-heptene        (CF₃CF₂CF═CHCF₂C₂F₅); pentafluoroethyl trifluorovinyl ether        (CF₂═CFOCF₂CF₃); and trifluoromethyl trifluorovinyl ether        (CF₂═CFOCF₃).

In addition, sub-cooling has been found to enhance the performance andefficiency of systems which use cross-current/counter-current heatexchange, such as those which employ either a dual-row condenser or adual-row evaporator.

Therefore, further in accordance with the method of the presentinvention, the present disclosure also provides that the condensing stepmay comprise:

-   -   (i) circulating the working fluid to a back row of the dual-row        condenser, where the back row receives the working fluid at a        first temperature; and    -   (ii) circulating the working fluid to a front row of the        dual-row condenser, where the front row receives the working        fluid at a second temperature, where the second temperature is        less than the first temperature, so that air which travels        across the front row and the back row is preheated, whereby the        temperature of the air is greater when it reaches the back row        than when it reaches the front row.

Further in accordance with the method of the present invention, thepresent disclosure also provides that the evaporating step may comprise:

-   -   (i) passing the working fluid through an inlet of a dual-row        evaporator having a first row and a second row,    -   (ii) circulating the working fluid in a first row in a direction        perpendicular to the flow of fluid through the inlet of the        evaporator, and    -   (iii) circulating the working fluid in a second row in a        direction generally counter to the direction of the flow of the        working fluid through the inlet.

Also in accordance with the present invention, there is provided a vaporcompression heat transfer system for exchanging heat comprising anintermediate heat exchanger in combination with a dual-row condenser ora dual-row evaporator, or both.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be better understood with reference to thefollowing figures, wherein:

FIG. 1 is a schematic diagram of one embodiment of a vapor compressionheat transfer system including an intermediate heat exchanger, used topractice the method of circulating a working fluid comprising afluoroolefin through this system according to the present invention.

FIG. 1A is a cross-sectional view of one embodiment of an intermediateheat exchanger.

FIG. 2 is a perspective view of a dual-row condenser which can be usedwith the vapor compression heat transfer system of FIG. 1.

FIG. 3 is a perspective view of a dual-row evaporator used which can beused with the vapor compression heat transfer system of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

One embodiment of the present disclosure provides a method ofcirculating a working fluid comprising a fluoroolefin through a vaporcompression heat transfer system. A vapor-compression heat transfersystem is a closed loop system which re-uses working fluid in multiplesteps producing a cooling effect in one step and a heating effect in adifferent step. Such a system generally includes an evaporator, acompressor, a condenser and an expansion device, and is known in theart. Reference will be made to FIG. 1 in describing this method.

With reference to FIG. 1, liquid working fluid from a condenser 41 flowsthrough a line to an intermediate heat exchanger, or simply IHX. Theintermediate heat exchanger includes a first tube 30, which contains arelatively hot liquid working fluid, and a second tube 50, whichcontains a relatively colder gaseous working fluid. The first tube ofthe IHX is connected to the outlet line of the condenser. The liquidworking fluid then flows through an expansion device 52 and through aline 62 to an evaporator 42, which is located in the vicinity of a bodyto cooled. In the evaporator, the working fluid is evaporated, and thevaporization of the working fluid provides cooling. The expansion device52 may be an expansion valve, a capillary tube, an orifice tube or anyother device where the working fluid may undergo an abrupt reduction inpressure. The evaporator has an outlet, through which the cold gaseousworking fluid flows to the second tube 50 of the IHX, wherein the coldgaseous working fluid comes in thermal contact with the hot liquidworking fluid in the first tube 30 of the IHX, and thus the cold gaseousworking fluid is warmed somewhat. The gaseous working fluid flows fromthe second tube of the IHX through a line 63 to the inlet of acompressor 12. The gas is compressed in the compressor, and thecompressed gaseous working fluid is discharged from the compressor andflows to the condenser 41 through a line 61 wherein the working fluid iscondensed, thus giving off heat, and the cycle then repeats.

In an intermediate heat exchanger, the first tube containing therelatively hotter liquid working fluid and the second tube containingthe relatively colder gaseous working fluid are in thermal contact, thusallowing transfer of heat from the hot liquid to the cold gas. The meansby which the two tubes are in thermal contact may vary. In oneembodiment, the first tube has a larger diameter than the second tube,and the second tube is disposed concentrically in the first tube, and ahot liquid in the first tube surrounds a cold gas in the second tube.This embodiment is shown in FIG. 1A, where the first tube (30 a)surrounds the second tube (50 a).

Also, in one embodiment, the working fluid in the second tube of theinternal heat exchanger may flow in a countercurrent direction to thedirection of flow of the working fluid in the first tube, therebycooling the working fluid in the first tube and heating the workingfluid in the second tube.

Cross-current/counter-current heat exchange may be provided in thesystem of FIG. 1 by a dual-row condenser or a dual-row evaporator,although it should be noted that this system is not limited to such adual-row condensers or evaporators. Such condensers and evaporators aredescribed in detail in U.S. Provisional Patent Application No.60/875,982, filed Dec. 19, 2006 (now International ApplicationPCT/US07/25675, filed Dec. 17, 2007), and may be designed particularlyfor working fluids that comprise non-azeotropic or near-azeotropiccompositions.

Therefore, in accordance with the present invention, there is provided avapor compression heat transfer system which comprises either a dual-rowcondenser, or a dual-row evaporator, or both. Such a system is the sameas that described above with respect to FIG. 1, except for thedescription of the dual-row condenser or the dual-row evaporator.

Reference will be made to FIG. 2 to describe such a system whichincludes a dual-row condenser. A dual-row condenser is shown at 41 inFIG. 2. In this dual-row cross-current/counter-current design, a hotworking fluid enters the condenser through a first, or back row 14,passes through the first row, and exits the condenser through a second,or front row 13. The working fluid enters first row 14 via a collector 6inside a first pass 2 of the first row. In the first, or back row, theworking fluid is cooled in a counter current manner by air, which hasbeen heated by the second, or front row 13 of this dual-row condenser.The working fluid goes from first pass 2 of the first row 14, to a pass3 of the second, or front row 13 by a connection 7. The working fluidthen flows from pass 3 to a pass 4 in second row 13 through a connection8, and then flows from pass 4 to a pass 5 through a connection 9. Thenthe sub-cooled working fluid exits the condenser by a connection 10. Airis circulated in a counter-current manner relative to the working fluidflow, as indicated by the arrow having points 11 and 12 of FIG. 2. Thedesign shown in FIG. 2 is generic and can be used for anyair-to-refrigerant condenser in stationary applications as well as inmobile applications.

Reference will be made to FIG. 3 in describing a vapor compression heattransfer system comprising a dual-row evaporator. A dual-row evaporatoris shown at 42 in FIG. 3. In this dual-row cross-current/counter-currentdesign, working fluid enters the evaporator through a first, or frontrow 17, passes through the first row, and exits the condenser through asecond, or back row 18. In particular, the working fluid enters theevaporator 19 at the lowest temperature through a collector 24 as shownin FIG. 3. Then the working fluid flows downwards through a tank 20 to atank 21 through a collector 25, then from tank 21 to a tank 22 in theback row through a collector 26. The working fluid then flows from tank22 to a tank 23 through a collector 27, and finally exits the evaporatorthrough a collector 28. Air is circulated in a cross-countercurrentarrangement as indicated by the arrow having points 29 and 30, of FIG.3.

In the embodiments as shown in FIGS. 1, 1A, 2 and 3, the connectinglines between the components of the vapor compression heat transfersystem, through which the working fluid may flow, may be constructed ofany typical conduit material known for such purpose. In one embodiment,metal piping or metal tubing (such as aluminum or copper or copper alloytubing) may be used to connect the components of the heat transfersystem. In another embodiment, hoses, constructed of various materials,such as polymers or elastomers, or combinations of such materials withreinforcing materials such as metal mesh etc., may be used in thesystem. One example of a hose design for heat transfer systems, inparticular for automobile air conditioning systems, is provided in U.S.Provisional Patent Application No. 60/841,713, filed Sep. 1, 2006 (nowInternational Application PCT/US07/019,205 filed Aug. 31, 2007 andpublished as WO2008-027255A1 on Mar. 6, 2008). For the tubes of the IHX,metal piping or tubing provides more efficient transfer of heat from thehot liquid working fluid to the cold gaseous working fluid.

Various types of compressors may be used in the vapor compression heattransfer system of the embodiments of the present invention, includingreciprocating, rotary, jet, centrifugal, scroll, screw or axial-flow,depending on the mechanical means to compress the fluid, or aspositive-displacement (e.g., reciprocating, scroll or screw) or dynamic(e.g., centrifugal or jet).

In certain embodiments the heat transfer systems as disclosed herein mayemploy fin and tube heat exchangers, microchannel heat exchangers andvertical or horizontal single pass tube or plate type heat exchangers,among others for both the evaporator and condenser.

The closed loop vapor compression heat transfer system as describedherein may be used in stationary refrigeration, air-conditioning, andheat pumps or mobile air-conditioning and refrigeration systems.Stationary air-conditioning and heat pump applications include window,ductless, ducted, packaged terminal, chillers and light commercial andcommercial air-conditioning systems, including packaged rooftop.Refrigeration applications include domestic or home refrigerators andfreezers, ice machines, self-contained coolers and freezers, walk-incoolers and freezers and supermarket systems, and transportrefrigeration systems.

Mobile refrigeration or mobile air-conditioning systems refer to anyrefrigeration or air-conditioning system incorporated into atransportation unit for the road, rail, sea or air. In addition,apparatus, which are meant to provide refrigeration or air-conditioningfor a system independent of any moving carrier, known as “intermodal”systems, are included in the present invention. Such intermodal systemsinclude “containers” (combined sea/land transport) as well as “swapbodies” (combined road and rail transport). The present invention isparticularly useful for road transport refrigerating or air-conditioningapparatus, such as automobile air-conditioning apparatus or refrigeratedroad transport equipment.

The working fluid utilized in the vapor compression heat transfer systemcomprises at least one fluoroolefin. By fluoroolefin is meant anycompound containing carbon, fluorine and optionally, hydrogen or oxygenthat also contains at least one double bond. These fluoroolefins may belinear, branched or cyclic.

Fluoroolefins have a variety of utilities in working fluids, whichinclude use as foaming agents, blowing agents, fire extinguishingagents, heat transfer mediums (such as heat transfer fluids andrefrigerants for use in refrigeration systems, refrigerators,air-conditioning systems, heat pumps, chillers, and the like), to name afew.

In some embodiments, heat transfer compositions may comprisefluoroolefins comprising at least one compound with 2 to 12 carbonatoms, in another embodiment the fluoroolefins comprise compounds with 3to 10 carbon atoms, and in yet another embodiment the fluoroolefinscomprise compounds with 3 to 7 carbon atoms. Representativefluoroolefins include but are not limited to all compounds as listed inTable 1, Table 2, and Table 3.

In one embodiment, the present methods use working fluids comprisingfluoroolefins having the formula E- or Z—R¹CH═CHR² (Formula I), whereinR¹ and R² are, independently, C₁ to C₆ perfluoroalkyl groups. Examplesof R¹ and R² groups include, but are not limited to, CF₃, C₂F₅,CF₂CF₂CF₃, CF(CF₃)₂, CF₂CF₂CF₂CF₃, CF(CF₃)CF₂CF₃, CF₂CF(CF₃)₂, C(CF₃)₃,CF₂CF₂CF₂CF₂CF₃, CF₂CF₂CF(CF₃)₂, C(CF₃)₂C₂F₅, CF₂CF₂CF₂CF₂CF₂CF₃,CF(CF₃) CF₂CF₂C₂F₅, and C(CF₃)₂CF₂C₂F₅. In one embodiment thefluoroolefins of Formula I, have at least about 4 carbon atoms in themolecule. In another embodiment, the fluoroolefins of Formula I have atleast about 5 carbon atoms in the molecule. Exemplary, non-limitingFormula I compounds are presented in Table 1.

TABLE 1 Code Structure Chemical Name F11E CF₃CH═CHCF₃1,1,1,4,4,4-hexafluorobut-2-ene F12E CF₃CH═CHC₂F₅1,1,1,4,4,5,5,5-octafluoropent-2-ene F13E CF₃CH═CHCF₂C₂F₅1,1,1,4,4,5,5,6,6,6-decafluorohex-2-ene F13iE CF₃CH═CHCF(CF₃)₂1,1,1,4,5,5,5-heptafluoro-4-(trifluoromethyl)pent-2- ene F22EC₂F₅CH═CHC₂F₅ 1,1,1,2,2,5,5,6,6,6-decafluorohex-3-ene F14ECF₃CH═CH(CF₂)₃CF₃ 1,1,1,4,4,5,5,6,6,7,7,7-dodecafluorohept-2-ene F14iECF₃CH═CHCF₂CF—(CF₃)₂1,1,1,4,4,5,6,6,6-nonafluoro-5-(trifluoromethyl)hex-2- ene F14sECF₃CH═CHCF(CF₃)—C₂F₅1,1,1,4,5,5,6,6,6-nonfluoro-4-(trifluoromethyl)hex-2- ene F14tECF₃CH═CHC(CF₃)₃ 1,1,1,5,5,5-hexafluoro-4,4-bis(trifluoromethyl)pent-2-ene F23E C₂F₅CH═CHCF₂C₂F₅ 1,1,1,2,2,5,5,6,6,7,7,7-dodecafluorohept-3-eneF23iE C₂F₅CH═CHCF(CF₃)₂1,1,1,2,2,5,6,6,6-nonafluoro-5-(trifluoromethyl)hex-3- ene F15ECF₃CH═CH(CF₂)₄CF₃ 1,1,1,4,4,5,5,6,6,7,7,8,8,8-tetradecafluorooct-2-eneF15iE CF₃CH═CH—CF₂CF₂CF(CF₃)₂ 1,1,1,4,4,5,5,6,7,7,7-undecafluoro-6-(trifluoromethyl)hept-2-ene F15tE CF₃CH═CH—C(CF₃)₂C₂F₅1,1,1,5,5,6,6,6-octafluoro-4,4-bis(trifluoromethyl)hex- 2-ene F24EC₂F₅CH═CH(CF₂)₃CF₃ 1,1,1,2,2,5,5,6,6,7,7,8,8,8-tetradecafluorooct-3-eneF24iE C₂F₅CH═CHCF₂CF—(CF₃)₂ 1,1,1,2,2,5,5,6,7,7,7-undecafluoro-6-(trifluoromethyl)hept-3-ene F24sE C₂F₅CH═CHCF(CF₃)—C₂F₅1,1,1,2,2,5,6,6,7,7,7-undecafluoro-5- (trifluoromethyl)hept-3-ene F24tEC₂F₅CH═CHC(CF₃)₃ 1,1,1,2,2,6,6,6-octafluoro-5,5-bis(trifluoromethyl)hex-3-ene F33E C₂F₅CF₂CH═CH—CF₂C₂F₅1,1,1,2,2,3,3,6,6,7,7,8,8,8-tetradecafluorooct-4-ene F3i3iE(CF₃)₂CFCH═CH—CF(CF₃)₂1,1,1,2,5,6,6,6-octafluoro-2,5-bis(trifluoromethyl)hex- 3-ene F33iEC₂F₅CF₂CH═CH—CF(CF₃)₂ 1,1,1,2,5,5,6,6,7,7,7-undecafluoro-2-(trifluoromethyl)hept-3-ene F16E CF₃CH═CH(CF₂)₅CF₃1,1,1,4,4,5,5,6,6,7,7,8,8,,9,9,9-hexadecafluoronon-2- ene F16sECF₃CH═CHCF(CF₃)(CF₂)₂C₂F₅ 1,1,1,4,5,5,6,6,7,7,8,8,8-tridecafluoro-4-(trifluoromethyl)hept-2-ene F16tE CF₃CH═CHC(CF₃)₂CF₂C₂F₅1,1,1,6,6,6-octafluoro-4,4-bis(trifluoromethyl)hept-2- ene F25EC₂F₅CH═CH(CF₂)₄CF₃ 1,1,1,2,2,5,5,6,6,7,7,8,8,9,9,9-hexadecafluoronon-3-ene F25iE C₂F₅CH═CH—CF₂CF₂CF(CF₃)₂1,1,1,2,2,5,5,6,6,7,8,8,8-tridecafluoro-7- (trifluoromethyl)oct-3-eneF25tE C₂F₅CH═CH—C(CF₃)₂C₂F₅ 1,1,1,2,2,6,6,7,7,7-decafluoro-5,5-bis(trifluoromethyl)hept-3-ene F34E C₂F₅CF₂CH═CH—(CF₂)₃CF₃1,1,1,2,2,3,3,6,6,7,7,8,8,9,9,9-hexadecafluoronon-4- ene F34iEC₂F₅CF₂CH═CH—CF₂CF(CF₃)₂ 1,1,1,2,2,3,3,6,6,7,8,8,8-tridecafluoro-7-(trifluoromethyl)oct-4-ene F34sE C₂F₅CF₂CH═CH—CF(CF₃)C₂F₅1,1,1,2,2,3,3,6,7,7,8,8,8-tridecafluoro-6- (trifluoromethyl)oct-4-eneF34tE C₂F₅CF₂CH═CH—C(CF₃)₃ 1,1,1,5,5,6,6,7,7,7-decafluoro-2,2-bis(trifluoromethyl)hept-3-ene F3i4E (CF₃)₂CFCH═CH—(CF₂)₃CF₃1,1,1,2,5,5,6,6,7,7,8,8,8-tridecafluoro- 2(trifluoromethyl)oct-3-eneF3i4iE (CF₃)₂CFCH═CH—CF₂CF(CF₃)₂ 1,1,1,2,5,5,6,7,7,7-decafluoro-2,6-bis(trifluoromethyl)hept-3-ene F3i4sE (CF₃)₂CFCH═CH—CF(CF₃)C₂F₅1,1,1,2,5,6,6,7,7,7-decafluoro-2,5- bis(trifluoromethyl)hept-3-eneF3i4tE (CF₃)₂CFCH═CH—C(CF₃)₃ 1,1,1,2,6,6,6-heptafluoro-2,5,5-tris(trifluoromethyl)hex-3-ene F26E C₂F₅CH═CH(CF₂)₅CF₃1,1,1,2,2,5,5,6,6,7,7,8,8,9,9,10,10,10- octadecafluorodec-3-ene F26sEC₂F₅CH═CHCF(CF₃)(CF₂)₂C₂F₅1,1,1,2,2,5,6,6,7,7,8,8,9,9,9-pentadecafluoro-5-(trifluoromethyl)non-3-ene F26tE C₂F₅CH═CHC(CF₃)₂CF₂C₂F₅1,1,1,2,2,6,6,7,7,8,8,8-dodecafluoro-5,5- bis(trifluoromethyl)oct-3-eneF35E C₂F₅CF₂CH═CH—(CF₂)₄CF₃ 1,1,1,2,2,3,3,6,6,7,7,8,8,9,9,10,10,10-octadecafluorodec-4-ene F35iE C₂F₅CF₂CH═CH—CF₂CF₂CF(CF₃)₂1,1,1,2,2,3,3,6,6,7,7,8,9,9,9-pentadecafluoro-8-(trifluoromethyl)non-4-ene F35tE C₂F₅CF₂CH═CH—C(CF₃)₂C₂F₅1,1,1,2,2,3,3,7,7,8,8,8-dodecafluoro-6,6- bis(trifluoromethyl)oct-4-eneF3i5E (CF₃)₂CFCH═CH—(CF₂)₄CF₃1,1,1,2,5,5,6,6,7,7,8,8,9,9,9-pentadecafluoro-2-(trifluoromethyl)non-3-ene F3i5iE (CF₃)₂CFCH═CH—CF₂CF₂CF(CF₃)₂1,1,1,2,5,5,6,6,7,8,8,8-dodecafluoro-2,7- bis(trifluoromethyl)oct-3-eneF3i5tE (CF₃)₂CFCH═CH—C(CF₃)₂C₂F₅ 1,1,1,2,6,6,7,7,7-nonafluoro-2,5,5-tris(trifluoromethyl)hept-3-ene F44E CF₃(CF₂)₃CH═CH—(CF₂)₃CF₃1,1,1,2,2,3,3,4,4,7,7,8,8,9,9,10,10,10- octadecafluorodec-5-ene F44iECF₃(CF₂)₃CH═CH—CF₂CF(CF₃)₂1,1,1,2,3,3,6,6,7,7,8,8,9,9,9-pentadecafluoro-2-(trifluoromethyl)non-4-ene F44sE CF₃(CF₂)₃CH═CH—CF(CF₃)C₂F₅1,1,1,2,2,3,6,6,7,7,8,8,9,9,9-pentadecafluoro-3-(trifluoromethyl)non-4-ene F44tE CF₃(CF₂)₃CH═CH—C(CF₃)₃1,1,1,5,5,6,6,7,7,8,8,8-dodecafluoro-2,2,- bis(trifluoromethyl)oct-3-eneF4i4iE (CF₃)₂CFCF₂CH═CH—CF₂CF(CF₃)₂1,1,1,2,3,3,6,6,7,8,8,8-dodecafluoro-2,7- bis(trifluoromethyl)oct-4-eneF4i4sE (CF₃)₂CFCF₂CH═CH—CF(CF₃)C₂F₅1,1,1,2,3,3,6,7,7,8,8,8-dodecafluoro-2,6- bis(trifluoromethyl)oct-4-eneF4i4tE (CF₃)₂CFCF₂CH═CH—C(CF₃)₃ 1,1,1,5,5,6,7,7,7-nonafluoro-2,2,6-tris(trifluoromethyl)hept-3-ene F4s4sE C₂F₅CF(CF₃)CH═CH—CF(CF₃)C₂F₅1,1,1,2,2,3,6,7,7,8,8,8-dodecafluoro-3,6- bis(trifluoromethyl)oct-4-eneF4s4tE C₂F₅CF(CF₃)CH═CH—C(CF₃)₃ 1,1,1,5,6,6,7,7,7-nonafluoro-2,2,5-tris(trifluoromethyl)hept-3-ene F4t4tE (CF₃)₃CCH═CH—C(CF₃)₃1,1,1,6,6,6-hexafluoro-2,2,5,5- tetrakis(trifluoromethyl)hex-3-ene

Compounds of Formula I may be prepared by contacting a perfluoroalkyliodide of the formula R¹¹ with a perfluoroalkyltrihydroolefin of theformula R²CH═CH₂ to form a trihydroiodoperfluoroalkane of the formulaR¹CH₂CHIR². This trihydroiodoperfluoroalkane can then bedehydroiodinated to form R¹CH═CHR². Alternatively, the olefin R¹CH═CHR²may be prepared by dehydroiodination of a trihydroiodoperfluoroalkane ofthe formula R¹CHICH₂R² formed in turn by reacting a perfluoroalkyliodide of the formula R²I with a perfluoroalkyltrihydroolefin of theformula R¹CH═CH₂.

Said contacting of a perfluoroalkyl iodide with aperfluoroalkyltrihydroolefin may take place in batch mode by combiningthe reactants in a suitable reaction vessel capable of operating underthe autogenous pressure of the reactants and products at reactiontemperature. Suitable reaction vessels include fabricated from stainlesssteels, in particular of the austenitic type, and the well-known highnickel alloys such as Monel® nickel-copper alloys, Hastelloy® nickelbased alloys and Inconel® nickel-chromium alloys.

Alternatively, the reaction may take be conducted in semi-batch mode inwhich the perfluoroalkyltrihydroolefin reactant is added to theperfluoroalkyl iodide reactant by means of a suitable addition apparatussuch as a pump at the reaction temperature.

The ratio of perfluoroalkyl iodide to perfluoroalkyltrihydroolefinshould be between about 1:1 to about 4:1, preferably from about 1.5:1 to2.5:1. Ratios less than 1.5:1 tend to result in large amounts of the 2:1adduct as reported by Jeanneaux, et. al. in Journal of FluorineChemistry, Vol. 4, pages 261-270 (1974).

Preferred temperatures for contacting of said perfluoroalkyl iodide withsaid perfluoroalkyltrihydroolefin are preferably within the range ofabout 150° C. to 300° C., preferably from about 170° C. to about 250°C., and most preferably from about 180° C. to about 230° C.

Suitable contact times for the reaction of the perfluoroalkyl iodidewith the perfluoroalkyltrihydroolefin are from about 0.5 hour to 18hours, preferably from about 4 to about 12 hours.

The trihydroiodoperfluoroalkane prepared by reaction of theperfluoroalkyl iodide with the perfluoroalkyltrihydroolefin may be useddirectly in the dehydroiodination step or may preferably be recoveredand purified by distillation prior to the dehydroiodination step.

The dehydroiodination step is carried out by contacting thetrihydroiodoperfluoroalkane with a basic substance. Suitable basicsubstances include alkali metal hydroxides (e.g., sodium hydroxide orpotassium hydroxide), alkali metal oxide (for example, sodium oxide),alkaline earth metal hydroxides (e.g., calcium hydroxide), alkalineearth metal oxides (e.g., calcium oxide), alkali metal alkoxides (e.g.,sodium methoxide or sodium ethoxide), aqueous ammonia, sodium amide, ormixtures of basic substances such as soda lime. Preferred basicsubstances are sodium hydroxide and potassium hydroxide.

Said contacting of the trihydroiodoperfluoroalkane with a basicsubstance may take place in the liquid phase preferably in the presenceof a solvent capable of dissolving at least a portion of both reactants.Solvents suitable for the dehydroiodination step include one or morepolar organic solvents such as alcohols (e.g., methanol, ethanol,n-propanol, isopropanol, n-butanol, isobutanol, and tertiary butanol),nitriles (e.g., acetonitrile, propionitrile, butyronitrile,benzonitrile, or adiponitrile), dimethyl sulfoxide,N,N-dimethylformamide, N,N-dimethylacetamide, or sulfolane. The choiceof solvent may depend on the boiling point product and the ease ofseparation of traces of the solvent from the product duringpurification. Typically, ethanol or isopropanol are good solvents forthe reaction.

Typically, the dehydroiodination reaction may be carried out by additionof one of the reactants (either the basic substance or thetrihydroiodoperfluoroalkane) to the other reactant in a suitablereaction vessel. Said reaction may be fabricated from glass, ceramic, ormetal and is preferably agitated with an impeller or stirring mechanism.

Temperatures suitable for the dehydroiodination reaction are from about10° C. to about 100° C., preferably from about 20° C. to about 70° C.The dehydroiodination reaction may be carried out at ambient pressure orat reduced or elevated pressure. Of note are dehydroiodination reactionsin which the compound of Formula I is distilled out of the reactionvessel as it is formed.

Alternatively, the dehydroiodination reaction may be conducted bycontacting an aqueous solution of said basic substance with a solutionof the trihydroiodoperfluoroalkane in one or more organic solvents oflower polarity such as an alkane (e.g., hexane, heptane, or octane),aromatic hydrocarbon (e.g., toluene), halogenated hydrocarbon (e.g.,methylene chloride, chloroform, carbon tetrachloride, orperchloroethylene), or ether (e.g., diethyl ether, methyl tert-butylether, tetrahydrofuran, 2-methyl tetrahydrofuran, dioxane,dimethoxyethane, diglyme, or tetraglyme) in the presence of a phasetransfer catalyst. Suitable phase transfer catalysts include quaternaryammonium halides (e.g., tetrabutylammonium bromide, tetrabutylammoniumhydrosulfate, triethylbenzylammonium chloride, dodecyltrimethylammoniumchloride, and tricaprylylmethylammonium chloride), quaternaryphosphonium halides (e.g., triphenylmethylphosphonium bromide andtetraphenylphosphonium chloride), or cyclic polyether compounds known inthe art as crown ethers (e.g., 18-crown-6 and 15-crown-5).

Alternatively, the dehydroiodination reaction may be conducted in theabsence of solvent by adding the trihydroiodoperfluoroalkane to a solidor liquid basic substance.

Suitable reaction times for the dehydroiodination reactions are fromabout 15 minutes to about six hours or more depending on the solubilityof the reactants. Typically the dehydroiodination reaction is rapid andrequires about 30 minutes to about three hours for completion. Thecompound of formula I may be recovered from the dehydroiodinationreaction mixture by phase separation after addition of water, bydistillation, or by a combination thereof.

In another embodiment of the present invention, fluoroolefins comprisecyclic fluoroolefins (cyclo-[CX═CY(CZW)_(n)—] (Formula II), wherein X,Y, Z, and W are independently selected from H and F, and n is an integerfrom 2 to 5). In one embodiment the fluoroolefins of Formula II, have atleast about 3 carbon atoms in the molecule. In another embodiment, thefluoroolefins of Formula II have at least about 4 carbon atoms in themolecule. In yet another embodiment, the fluoroolefins of Formula IIhave at least about 5 carbon atoms in the molecule. Representativecyclic fluoroolefins of Formula II are listed in Table 2.

TABLE 2 Cyclic fluoroolefins Structure Chemical name FC-C1316cccyclo-CF₂CF₂CF═CF— 1,2,3,3,4,4- hexafluorocyclobutene HFC-cyclo-CF₂CF₂CH═CH— 3,3,4,4- C1334cc tetrafluorocyclobutene HFC-C1436cyclo-CF₂CF₂CF₂CH═CH— 3,3,4,4,5,5,- hexafluorocyclopentene FC-C1418ycyclo-CF₂CF═CFCF₂CF₂— 1,2,3,3,4,4,5,5- octafluorocyclopentene FC-C151-cyclo-CF₂CF═CFCF₂CF₂CF₂— 1,2,3,3,4,4,5,5,6,6- 10y decafluorocyclohexene

The compositions of the present invention may comprise a single compoundof Formula I or formula II, for example, one of the compounds in Table 1or Table 2, or may comprise a combination of compounds of Formula I orformula II.

In another embodiment, fluoroolefins may comprise those compounds listedin Table 3.

TABLE 3 Name Structure Chemical name HFC-1225ye CF₃CF═CHF1,2,3,3,3-pentafluoro-1-propene HFC-1225zc CF₃CH═CF₂1,1,3,3,3-pentafluoro-1-propene HFC-1225yc CHF₂CF═CF₂1,1,2,3,3-pentafluoro-1-propene HFC-1234ye CHF₂CF═CHF1,2,3,3-tetrafluoro-1-propene HFC-1234yf CF₃CF═CH₂2,3,3,3-tetrafluoro-1-propene HFC-1234ze CF₃CH═CHF1,3,3,3-tetrafluoro-1-propene HFC-1234yc CH₂FCF═CF₂1,1,2,3-tetrafluoro-1-propene HFC-1234zc CHF₂CH═CF₂1,1,3,3-tetrafluoro-1-propene HFC-1243yf CHF₂CF═CH₂2,3,3-trifluoro-1-propene HFC-1243zf CF₃CH═CH₂ 3,3,3-trifluoro-1-propeneHFC-1243yc CH₃CF═CF₂ 1,1,2-trifluoro-1-propene HFC-1243zc CH₂FCH═CF₂1,1,3-trifluoro-1-propene HFC-1243ye CH₂FCF═CHF1,2,3-trifluoro-1-propene HFC-1243ze CHF₂CH═CHF1,3,3-trifluoro-1-propene FC-1318my CF₃CF═CFCF₃1,1,1,2,3,4,4,4-octafluoro-2-butene FC-1318cy CF₃CF₂CF═CF₂1,1,2,3,3,4,4,4-octafluoro-1-butene HFC-1327my CF₃CF═CHCF₃1,1,1,2,4,4,4-heptafluoro-2-butene HFC-1327ye CHF═CFCF₂CF₃1,2,3,3,4,4,4-heptafluoro-1-butene HFC-1327py CHF₂CF═CFCF₃1,1,1,2,3,4,4-heptafluoro-2-butene HFC-1327et (CF₃)₂C═CHF1,3,3,3-tetrafluoro-2-(trifluoromethyl)-1- propene HFC-1327czCF₂═CHCF₂CF₃ 1,1,3,3,4,4,4-heptafluoro-1-butene HFC-1327cye CF₂═CFCHFCF₃1,1,2,3,4,4,4-heptafluoro-1-butene HFC-1327cyc CF₂═CFCF₂CHF₂1,1,2,3,3,4,4-heptafluoro-1-butene HFC-1336yf CF₃CF₂CF═CH₂2,3,3,4,4,4-hexafluoro-1-butene HFC-1336ze CHF═CHCF₂CF₃1,3,3,4,4,4-hexafluoro-1-butene HFC-1336eye CHF═CFCHFCF₃1,2,3,4,4,4-hexafluoro-1-butene HFC-1336eyc CHF═CFCF₂CHF₂1,2,3,3,4,4-hexafluoro-1-butene HFC-1336pyy CHF₂CF═CFCHF₂1,1,2,3,4,4-hexafluoro-2-butene HFC-1336qy CH₂FCF═CFCF₃1,1,1,2,3,4-hexafluoro-2-butene HFC-1336pz CHF₂CH═CFCF₃1,1,1,2,4,4-hexafluoro-2-butene HFC-1336mzy CF₃CH═CFCHF₂1,1,1,3,4,4-hexafluoro-2-butene HFC-1336qc CF₂═CFCF₂CH₂F1,1,2,3,3,4-hexafluoro-1-butene HFC-1336pe CF₂═CFCHFCHF₂1,1,2,3,4,4-hexafluoro-1-butene HFC-1336ft CH₂═C(CF₃)₂3,3,3-trifluoro-2-(trifluoromethyl)-1-propene HFC-1345qz CH₂FCH═CFCF₃1,1,1,2,4-pentafluoro-2-butene HFC-1345mzy CF₃CH═CFCH₂F1,1,1,3,4-pentafluoro-2-butene HFC-1345fz CF₃CF₂CH═CH₂3,3,4,4,4-pentafluoro-1-butene HFC-1345mzz CHF₂CH═CHCF₃1,1,1,4,4-pentafluoro-2-butene HFC-1345sy CH₃CF═CFCF₃1,1,1,2,3-pentafluoro-2-butene HFC-1345fyc CH₂═CFCF₂CHF₂2,3,3,4,4-pentafluoro-1-butene HFC-1345pyz CHF₂CF═CHCHF₂1,1,2,4,4-pentafluoro-2-butene HFC-1345cyc CH₃CF₂CF═CF₂1,1,2,3,3-pentafluoro-1-butene HFC-1345pyy CH₂FCF═CFCHF₂1,1,2,3,4-pentafluoro-2-butene HFC-1345eyc CH₂FCF₂CF═CHF1,2,3,3,4-pentafluoro-1-butene HFC-1345ctm CF₂═C(CF₃)(CH₃)1,1,3,3,3-pentafluoro-2-methyl-1-propene HFC-1345ftp CH₂═C(CHF₂)(CF₃)2-(difluoromethyl)-3,3,3-trifluoro-1-propene HFC1345fye CH₂═CFCHFCF₃2,3,4,4,4-pentafluoro-1-butene HFC-1345eyf CHF═CFCH₂CF₃1,2,4,4,4-pentafluoro-1-butene HFC-1345eze CHF═CHCHFCF₃1,3,4,4,4-pentafluoro-1-butene HFC-1345ezc CHF═CHCF₂CHF₂1,3,3,4,4-pentafluoro-1-butene HFC-1345eye CHF═CFCHFCHF₂1,2,3,4,4-pentafluoro-1-butene HFC-1354fzc CH₂═CHCF₂CHF₂3,3,4,4-tetrafluoro-1-butene HFC-1354ctp CF₂═C(CHF₂)(CH₃)1,1,3,3-tetrafluoro-2-methyl-1-propene HFC-1354etm CHF═C(CF₃)(CH₃)1,3,3,3-tetrafluoro-2-methyl-1-propene HFC-1354tfp CH₂═C(CHF₂)₂2-(difluoromethyl)-3,3-difluoro-1-propene HFC-1354my CF₃CF═CHCH₃1,1,1,2-tetrafluoro-2-butene HFC-1354mzy CH₃CF═CHCF₃1,1,1,3-tetrafluoro-2-butene FC-141-10myy CF₃CF═CFCF₂CF₃1,1,1,2,3,4,4,5,5,5-decafluoro-2-pentene FC-141-10cy CF₂═CFCF₂CF₂CF₃1,1,2,3,3,4,4,5,5,5-decafluoro-1-pentene HFC-1429mzt (CF₃)₂C═CHCF₃1,1,1,4,4,4-hexafluoro-2-(trifluoromethyl)-2- butene HFC-1429myzCF₃CF═CHCF₂CF₃ 1,1,1,2,4,4,5,5,5-nonafluoro-2-pentene HFC-1429mzyCF₃CH═CFCF₂CF₃ 1,1,1,3,4,4,5,5,5-nonafluoro-2-pentene HFC-1429eycCHF═CFCF₂CF₂CF₃ 1,2,3,3,4,4,5,5,5-nonafluoro-1-pentene HFC-1429czcCF₂═CHCF₂CF₂CF₃ 1,1,3,3,4,4,5,5,5-nonafluoro-1-pentene HFC-1429cyccCF₂═CFCF₂CF₂CHF₂ 1,1,2,3,3,4,4,5,5-nonafluoro-1-pentene HFC-1429pyyCHF₂CF═CFCF₂CF₃ 1,1,2,3,4,4,5,5,5-nonafluoro-2-pentene HFC-1429myycCF₃CF═CFCF₂CHF₂ 1,1,1,2,3,4,4,5,5-nonafluoro-2-pentene HFC-1429myyeCF₃CF═CFCHFCF₃ 1,1,1,2,3,4,5,5,5-nonafluoro-2-pentene HFC-1429eyymCHF═CFCF(CF₃)₂ 1,2,3,4,4,4-hexafluoro-3-(trifluoromethyl)-1- buteneHFC-1429cyzm CF₂═CFCH(CF₃)₂1,1,2,4,4,4-hexafluoro-3-(trifluoromethyl)-1- butene HFC-1429mztCF₃CH═C(CF₃)₂ 1,1,1,4,4,4-hexafluoro-2-(trifluoromethyl)-2- buteneHFC-1429czym CF₂═CHCF(CF₃)₂1,1,3,4,4,4-hexafluoro-3-(trifluoromethyl)-1- butene HFC-1438fyCH₂═CFCF₂CF₂CF₃ 2,3,3,4,4,5,5,5-octafluoro-1-pentene HFC-1438eyccCHF═CFCF₂CF₂CHF₂ 1,2,3,3,4,4,5,5-octafluoro-1-pentene HFC-1438ftmcCH₂═C(CF₃)CF₂CF₃ 3,3,4,4,4-pentafluoro-2-(trifluoromethyl)-1- buteneHFC-1438czzm CF₂═CHCH(CF₃)₂ 1,1,4,4,4-pentafluoro-3-(trifluoromethyl)-1-butene HFC-1438ezym CHF═CHCF(CF₃)₂1,3,4,4,4-pentafluoro-3-(trifluoromethyl)-1- butene HFC-1438ctmfCF₂═C(CF₃)CH₂CF₃ 1,1,4,4,4-pentafluoro-2-(trifluoromethyl)-1- buteneHFC-1447fzy (CF₃)₂CFCH═CH₂ 3,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene HFC-1447fz CF₃CF₂CF₂CH═CH₂ 3,3,4,4,5,5,5-heptafluoro-1-penteneHFC-1447fycc CH₂═CFCF₂CF₂CHF₂ 2,3,3,4,4,5,5-heptafluoro-1-penteneHFC-1447czcf CF₂═CHCF₂CH₂CF₃ 1,1,3,3,5,5,5-heptafluoro-1-penteneHFC-1447mytm CF₃CF═C(CF₃)(CH₃) 1,1,1,2,4,4,4-heptafluoro-3-methyl-2-butene HFC-1447fyz CH₂═CFCH(CF₃)₂2,4,4,4-tetrafluoro-3-(trifluoromethyl)-1- butene HFC-1447ezzCHF═CHCH(CF₃)₂ 1,4,4,4-tetrafluoro-3-(trifluoromethyl)-1- buteneHFC-1447qzt CH₂FCH═C(CF₃)₂ 1,4,4,4-tetrafluoro-2-(trifluoromethyl)-2-butene HFC-1447syt CH₃CF═C(CF₃)₂2,4,4,4-tetrafluoro-2-(trifluoromethyl)-2- butene HFC-1456szt(CF₃)₂C═CHCH₃ 3-(trifluoromethyl)-4,4,4-trifluoro-2-butene HFC-1456szyCF₃CF₂CF═CHCH₃ 3,4,4,5,5,5-hexafluoro-2-pentene HFC-1456mstzCF₃C(CH₃)═CHCF₃ 1,1,1,4,4,4-hexafluoro-2-methyl-2-butene HFC-1456fzceCH₂═CHCF₂CHFCF₃ 3,3,4,5,5,5-hexafluoro-1-pentene HFC-1456ftmfCH₂═C(CF₃)CH₂CF₃ 4,4,4-trifluoro-2-(trifluoromethyl)-1-butene FC-151-12cCF₃(CF₂)₃CF═CF₂ 1,1,2,3,3,4,4,5,5,6,6,6-dodecafluoro-1- hexene (orperfluoro-1-hexene) FC-151-12mcy CF₃CF₂CF═CFCF₂CF₃1,1,1,2,2,3,4,5,5,6,6,6-dodecafluoro-3- hexene (or perfluoro-3-hexene)FC-151-12mmtt (CF₃)₂C═C(CF₃)₂ 1,1,1,4,4,4-hexafluoro-2,3-bis(trifluoromethyl)-2-butene FC-151-12mmzz (CF₃)₂CFCF═CFCF₃1,1,1,2,3,4,5,5,5-nonafluoro-4- (trifluoromethyl)-2-penteneHFC-152-11mmtz (CF₃)₂C═CHC₂F₅ 1,1,1,4,4,5,5,5-octafluoro-2-(trifluoromethyl)-2-pentene HFC-152- (CF₃)₂CFCF═CHCF₃1,1,1,3,4,5,5,5-octafluoro-4- 11mmyyz (trifluoromethyl)-2-pentene PFBECF₃CF₂CF₂CF₂CH═CH₂ 3,3,4,4,5,5,6,6,6-nonafluoro-1-hexene (or (orHFC-1549fz) perfluorobutylethylene) HFC-1549fztmm CH₂═CHC(CF₃)₃4,4,4-trifluoro-3,3-bis(trifluoromethyl)-1- butene HFC-1549mmtts(CF₃)₂C═C(CH₃)(CF₃) 1,1,1,4,4,4-hexafluoro-3-methyl-2-(trifluoromethyl)-2-butene HFC-1549fycz CH₂═CFCF₂CH(CF₃)₂2,3,3,5,5,5-hexafluoro-4-(trifluoromethyl)-1- pentene HFC-1549mytsCF₃CF═C(CH₃)CF₂CF₃ 1,1,1,2,4,4,5,5,5-nonafluoro-3-methyl-2- penteneHFC-1549mzzz CF₃CH═CHCH(CF₃)₂1,1,1,5,5,5-hexafluoro-4-(trifluoromethyl)-2- pentene HFC-1558szyCF₃CF₂CF₂CF═CHCH₃ 3,4,4,5,5,6,6,6-octafluoro-2-hexene HFC-1558fzcccCH₂═CHCF₂CF₂CF₂CHF₂ 3,3,4,4,5,5,6,6-octafluoro-2-hexene HFC-1558mmtzc(CF₃)₂C═CHCF₂CH₃ 1,1,1,4,4-pentafluoro-2-(trifluoromethyl)-2- penteneHFC-1558ftmf CH₂═C(CF₃)CH₂C₂F₅4,4,5,5,5-pentafluoro-2-(trifluoromethyl)-1- pentene HFC-1567ftsCF₃CF₂CF₂C(CH₃)═CH₂ 3,3,4,4,5,5,5-heptafluoro-2-methyl-1- penteneHFC-1567szz CF₃CF₂CF₂CH═CHCH₃ 4,4,5,5,6,6,6-heptafluoro-2-hexeneHFC-1567fzfc CH₂═CHCH₂CF₂C₂F₅ 4,4,5,5,6,6,6-heptafluoro-1-hexeneHFC-1567sfyy CF₃CF₂CF═CFC₂H₅ 1,1,1,2,2,3,4-heptafluoro-3-hexeneHFC-1567fzfy CH₂═CHCH₂CF(CF₃)₂4,5,5,5-tetrafluoro-4-(trifluoromethyl)-1- pentene HFC-1567myzzmCF₃CF═CHCH(CF₃)(CH₃) 1,1,1,2,5,5,5-heptafluoro-4-methyl-2- penteneHFC-1567mmtyf (CF₃)₂C═CFC₂H₅ 1,1,1,3-tetrafluoro-2-(trifluoromethyl)-2-pentene FC-161-14myy CF₃CF═CFCF₂CF₂C₂F₅1,1,1,2,3,4,4,5,5,6,6,7,7,7-tetradecafluoro- 2-heptene FC-161-14mcyyCF₃CF₂CF═CFCF₂C₂F₅ 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-2-heptene HFC-162-13mzy CF₃CH═CFCF₂CF₂C₂F₅1,1,1,3,4,4,5,5,6,6,7,7,7-tridecafluoro-2- heptene HFC162-13myzCF₃CF═CHCF₂CF₂C₂F₅ 1,1,1,2,4,4,5,5,6,6,7,7,7-tridecafluoro-2- hepteneHFC-162-13mczy CF₃CF₂CH═CFCF₂C₂F₅1,1,1,2,2,4,5,5,6,6,7,7,7-tridecafluoro-3- heptene HFC-162-13mcyzCF₃CF₂CF═CHCF₂C₂F₅ 1,1,1,2,2,3,5,5,6,6,7,7,7-tridecafluoro-3- heptenePEVE CF₂═CFOCF₂CF₃ pentafluoroethyl trifluorovinyl ether PMVE CF₂═CFOCF₃trifluoromethyl trifluorovinyl ether

The compounds listed in Table 2 and Table 3 are available commerciallyor may be prepared by processes known in the art or as described herein.

1,1,1,4,4-pentafluoro-2-butene may be prepared from1,1,1,2,4,4-hexafluorobutane (CHF₂CH₂CHFCF₃) by dehydrofluorination oversolid KOH in the vapor phase at room temperature. The synthesis of1,1,1,2,4,4-hexafluorobutane is described in U.S. Pat. No. 6,066,768,incorporated herein by reference.

1,1,1,4,4,4-hexafluoro-2-butene may be prepared from1,1,1,4,4,4-hexafluoro-2-iodobutane (CF₃CHICH₂CF₃) by reaction with KOHusing a phase transfer catalyst at about 60° C. The synthesis of1,1,1,4,4,4-hexafluoro-2-iodobutane may be carried out by reaction ofperfluoromethyl iodide (CF₃I) and 3,3,3-trifluoropropene (CF₃CH═CH₂) atabout 200° C. under autogenous pressure for about 8 hours.

3,4,4,5,5,5-hexafluoro-2-pentene may be prepared by dehydrofluorinationof 1,1,1,2,2,3,3-heptafluoropentane (CF₃CF₂CF₂CH₂CH₃) using solid KOH orover a carbon catalyst at 200-300° C. 1,1,1,2,2,3,3-heptafluoropentanemay be prepared by hydrogenation of 3,3,4,4,5,5,5-heptafluoro-1-pentene(CF₃CF₂CF₂CH═CH₂).

1,1,1,2,3,4-hexafluoro-2-butene may be prepared by dehydrofluorinationof 1,1,1,2,3,3,4-heptafluorobutane (CH₂FCF₂CHFCF₃) using solid KOH.

1,1,1,2,4,4-hexafluoro-2-butene may be prepared by dehydrofluorinationof 1,1,1,2,2,4,4-heptafluorobutane (CHF₂CH₂CF₂CF₃) using solid KOH.

1,1,1,3,4,4-hexafluoro2-butene may be prepared by dehydrofluorination of1,1,1,3,3,4,4-heptafluorobutane (CF₃CH₂CF₂CHF₂) using solid KOH.

1,1,1,2,4-pentafluoro-2-butene may be prepared by dehydrofluorination of1,1,1,2,2,3-hexafluorobutane (CH₂FCH₂CF₂CF₃) using solid KOH.

1,1,1,3,4-pentafluoro-2-butene may be prepared by dehydrofluorination of1,1,1,3,3,4-hexafluorobutane (CF₃CH₂CF₂CH₂F) using solid KOH.

1,1,1,3-tetrafluoro-2-butene may be prepared by reacting1,1,1,3,3-pentafluorobutane (CF₃CH₂CF₂CH₃) with aqueous KOH at 120° C.

1,1,1,4,4,5,5,5-octafluoro-2-pentene may be prepared from(CF₃CHICH₂CF₂CF₃) by reaction with KOH using a phase transfer catalystat about 60° C. The synthesis of4-iodo-1,1,1,2,2,5,5,5-octafluoropentane may be carried out by reactionof perfluoroethyliodide (CF₃CF₂I) and 3,3,3-trifluoropropene at about200° C. under autogenous pressure for about 8 hours.

1,1,1,2,2,5,5,6,6,6-decafluoro-3-hexene may be prepared from1,1,1,2,2,5,5,6,6,6-decafluoro-3-iodohexane (CF₃CF₂CHICH₂CF₂CF₃) byreaction with KOH using a phase transfer catalyst at about 60° C. Thesynthesis of 1,1,1,2,2,5,5,6,6,6-decafluoro-3-iodohexane may be carriedout by reaction of perfluoroethyliodide (CF₃CF₂I) and3,3,4,4,4-pentafluoro-1-butene (CF₃CF₂CH═CH₂) at about 200° C. underautogenous pressure for about 8 hours.

1,1,1,4,5,5,5-heptafluoro-4-(trifluoromethyl)-2-pentene may be preparedby the dehydrofluorination of1,1,1,2,5,5,5-heptafluoro-4-iodo-2-(trifluoromethyl)-pentane(CF₃CHICH₂CF(CF₃)₂) with KOH in isopropanol. CF₃CHICH₂CF(CF₃)₂ is madefrom reaction of (CF₃)₂CFI with CF₃CH═CH₂ at high temperature, such asabout 200° C.

1,1,1,4,4,5,5,6,6,6-decafluoro-2-hexene may be prepared by the reactionof 1,1,1,4,4,4-hexafluoro-2-butene (CF₃CH═CHCF₃) withtetrafluoroethylene (CF₂═CF₂) and antimony pentafluoride (SbF₅).

2,3,3,4,4-pentafluoro-1-butene may be prepared by dehydrofluorination of1,1,2,2,3,3-hexafluorobutane over fluorided alumina at elevatedtemperature.

2,3,3,4,4,5,5,5-ocatafluoro-1-pentene may be prepared bydehydrofluorination of 2,2,3,3,4,4,5,5,5-nonafluoropentane over solidKOH.

1,2,3,3,4,4,5,5-octafluoro-1-pentene may be prepared bydehydrofluorination of 2,2,3,3,4,4,5,5,5-nonafluoropentane overfluorided alumina at elevated temperature.

Many of the compounds of Formula I, Formula II, Table 1, Table 2, andTable 3 exist as different configurational isomers or stereoisomers.When the specific isomer is not designated, the described composition isintended to include all single configurational isomers, singlestereoisomers, or any combination thereof. For instance, F11E is meantto represent the E-isomer, Z-isomer, or any combination or mixture ofboth isomers in any ratio. As another example, HFC-1225ye is meant torepresent the E-isomer, Z-isomer, or any combination or mixture of bothisomers in any ratio, with the Z isomer preferred.

In some embodiments, the working fluid may further comprise at least onecompound selected from hydrofluorocarbons, fluoroethers, hydrocarbons,dimethyl ether (DME), carbon dioxide (CO₂), ammonia (NH₃), andiodotrifluoromethane (CF₃I).

In some embodiments, the working fluid may further comprisehydrofluorocarbons comprising at least one saturated compound containingcarbon, hydrogen, and fluorine. Of particular utility arehydrofluorocarbons having 1 to 7 carbon atoms and having a normalboiling point of from about −90° C. to about 80° C. Hydrofluorocarbonsare commercial products available from a number of sources or may beprepared by methods known in the art. Representative hydrofluorocarboncompounds include but are not limited to fluoromethane (CH₃F, HFC-41),difluoromethane (CH₂F₂, HFC-32), trifluoromethane (CHF₃, HFC-23),pentafluoroethane (CF₃CHF₂, HFC-125), 1,1,2,2-tetrafluoroethane(CHF₂CHF₂, HFC-134), 1,1,1,2-tetrafluoroethane (CF₃CH₂F, HFC-134a),1,1,1-trifluoroethane (CF₃CH₃, HFC-143a), 1,1-difluoroethane (CHF₂CH₃,HFC-152a), fluoroethane (CH₃CH₂F, HFC-161), (CF₃CF₂CHF₂, HFC-227ca),1,1,1,2,3,3,3-heptafluoropropane (CF₃CHFCF₃, HFC-227ea),1,2,2,3,3-hexafluoropropane (CHF₂CF₂CHF₂, HFC-236ca),1,1,1,2,2,3-hexafluoropropane (CF₃CF₃CH₂F, HFC-236cb),1,1,2,3,3-hexafluoropropane (CF₃CHFCHF₂, HFC-236ea),1,1,1,3,3,3-hexafluoropropane (CF₃CH₂CF₃, HFC-236fa),1,1,2,2,3-pentafluoropropane (CHF₂CF₂CH₂F, HFC-245ca),1,1,1,2,2-pentafluoropropane (CF₃CF₂CH₃, HFC-245cb),1,1,2,3,3-pentafluoropropane (CHF₂CHFCHF₂, HFC-245ea),1,1,1,2,3-pentafluoropropane (CF₃CHFCH₂F, HFC-245eb),1,1,1,3,3-pentafluoropropane (CF₃CH₂CHF₂, HFC-245fa),1,2,2,3-tetrafluoropropane (CH₂FCF₂CH₂F, HFC-254ca),1,1,2,2-tetrafluoropropane (CHF₂CF₂CH₃, HFC-254cb),1,1,2,3-tetrafluoropropane (CHF₂CHFCH₂F, HFC-254ea),1,1,1,2-tetrafluoropropane (CF₃CHFCH₃, HFC-254eb),1,1,3,3-tetrafluoropropane (CHF₂CH₂CHF₂, HFC-254fa),1,1,1,3-tetrafluoropropane (CF₃CH₂CH₂F, HFC-254fb),1,1,1-trifluoropropane (CF₃CH₂CH₃, HFC-263fb), 2,2-difluoropropane(CH₃CF₂CH₃, HFC-272ca), 1,2-difluoropropane (CH₂FCHFCH₃, HFC-272ea),1,3-difluoropropane (CH₂FCH₂CH₂F, HFC-272fa), 1,1-difluoropropane(CHF₂CH₂CH₃, HFC-272fb), 2-fluoropropane (CH₃CHFCH₃, HFC-281ea),1-fluoropropane (CH₂FCH₂CH₃, HFC-281fa),1,1,2,2,3,3,4,4-octafluorobutane (CHF₂CF₂CF₂CHF₂, HFC-338 pcc),1,1,1,2,2,4,4,4-octafluorobutane (CF₃CH₂CF₂CF₃, HFC-338mf),1,1,1,3,3-pentafluorobutane (CF₃CH₂CHF₂, HFC-365mfc),1,1,1,2,3,4,4,5,5,5-decafluoropentane (CF₃CHFCHFCF₂CF₃, HFC-43-10mee),and 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoroheptane(CF₃CF₂CHFCHFCF₂CF₂CF₃, HFC-63-14mee).

In some embodiments, working fluids may further comprise fluoroetherscomprising at least one compound having carbon, fluorine, oxygen andoptionally hydrogen, chlorine, bromine or iodine. Fluoroethers arecommercially available or may be produced by methods known in the art.Representative fluoroethers include but are not limited tononafluoromethoxybutane (C₄F₉OCH₃, any or all possible isomers ormixtures thereof); nonafluoroethoxybutane (C₄F₉OC₂H₅, any or allpossible isomers or mixtures thereof);2-difluoromethoxy-1,1,1,2-tetrafluoroethane (HFOC-236eaEβγ, orCNF₂OCHFCF₃); 1,1-difluoro-2-methoxyethane (HFOC-272fbEβγ, CH₃OCH₂CHF₂);1,1,1,3,3,3-hexafluoro-2-(fluoromethoxy)propane (HFOC-347mmzEβγ, orCH₂FOCH(CF₃)₂); 1,1,1,3,3,3-hexafluoro-2-methoxypropane (HFOC-356mmzEβγ,or CH₃OCH(CH₃)₂); 1,1,1,2,2-pentafluoro-3-methoxypropane (HFOC-365mcEγδ,or CF₃CF₂CH₂OCH₃); 2-ethoxy-1,1,1,2,3,3,3-heptafluoropropane(HFOC-467mmyEβγ, or CH₃CH₂OCF(CF₃)₂; and mixtures thereof.

In some embodiments, working fluids may further comprise hydrocarbonscomprising compounds having only carbon and hydrogen. Of particularutility are compounds having 3 to 7 carbon atoms. Hydrocarbons arecommercially available through numerous chemical suppliers.Representative hydrocarbons include but are not limited to propane,n-butane, isobutane, cyclobutane, n-pentane, 2-methylbutane,2,2-dimethylpropane, cyclopentane, n-hexane, 2-methylpentane,2,2-dimethylbutane, 2,3-dimethylbutane, 3-methylpentane, cyclohexane,n-heptane, and cycloheptane.

In some embodiments, the working fluid may comprise hydrocarbonscontaining heteroatoms, such as dimethylether (DME, CH₃OCH₃). DME iscommercially available.

In some embodiments, working fluids may further comprise carbon dioxide(CO₂), which is commercially available from various sources or may beprepared by methods known in the art.

In some embodiments, working fluids may further comprise ammonia (NH₃),which is commercially available from various sources or may be preparedby methods known in the art.

In some embodiments, the working fluid further comprises at least onecompound selected from hydrofluorocarbons, fluoroethers, hydrocarbons,dimethyl ether (DME), carbon dioxide (CO₂), ammonia (NH₃), andiodotrifluoromethane (CF₃I).

In one embodiment, the working fluid comprises1,2,3,3,3-pentafluoropropene (HFC-1225ye). In another embodiment, theworking fluid further comprises difluoromethane (HFC-32). In yet anotherembodiment, the working fluid further comprises1,1,1,2-tetrafluoroethane (HFC-134a).

In one embodiment, the working fluid comprises2,3,3,3-tetrafluoropropene (HFC-1234yf). In another embodiment, theworking fluid comprises HFC-1225ye and HFC-1234yf.

In one embodiment, the working fluid comprises1,3,3,3-tetrafluoropropene (HFC-1234ze). In another embodiment, theworking fluid comprises E-HFC-1234ze (or trans-HFC-1234ze).

In yet another embodiment, the working fluid further comprises at leastone compound from the group consisting of HFC-134a, HFC-32, HFC-125,HFC-152a, and CF₃I.

In certain embodiments, working fluids may comprise a compositionselected from the group consisting of:

HFC-32 and HFC-1225ye;

HFC-1234yf and CF₃I;

HFC-32, HFC-134a, and HFC-1225ye;

HFC-32, HFC-125, and HFC-1225ye;

HFC-32, HFC-1225ye, and HFC-1234yf;

HFC-125, HFC-1225ye, and HFC-1234yf;

HFC-32, HFC-1225ye, HFC-1234yf, and CF₃I;

HFC-134a, HFC-1225ye, and HFC-1234yf;

HFC-134a and HFC-1234yf;

HFC-32 and HFC-1234yf;

HFC-125 and HFC-1234yf;

HFC-32, HFC-125, and HFC-1234yf;

HFC-32, HFC-134a, and HFC-1234yf;

DME and HFC-1234yf;

HFC-152a and HFC-1234yf;

HFC-152a, HFC-134a, and HFC-1234yf;

HFC-152a, n-butane, and HFC-1234yf;

HFC-134a, propane, and HFC-1234yf;

HFC-125, HFC-152a, and HFC-1234yf;

HFC-125, HFC-134a, and HFC-1234yf;

HFC-32, HFC-1234ze, and HFC-1234yf;

HFC-125, HFC-1234ze, and HFC-1234yf;

HFC-32, HFC-1234ze, HFC-1234yf, and CF₃I;

HFC-134a, HFC-1234ze, and HFC-1234yf;

HFC-134a and HFC-1234ze;

HFC-32 and HFC-1234ze;

HFC-125 and HFC-1234ze;

HFC-32, HFC-125, and HFC-1234ze;

HFC-32, HFC-134a, and HFC-1234ze;

DME and HFC-1234ze;

HFC-152a and HFC-1234ze;

HFC-152a, HFC-134a, and HFC-1234ze;

HFC-152a, n-butane, and HFC-1234ze;

HFC-134a, propane, and HFC-1234ze;

HFC-125, HFC-152a, and HFC-1234ze; or

HFC-125, HFC-134a, and HFC-1234ze.

EXAMPLES Example 1 Performance Comparison

Automobile air conditioning systems with and without an intermediateheat exchanger are tested to determine if an improvement is seen withthe IHX. The working fluid is a blend of 95% by weight HFC-1225ye and 5%by weight of HFC-32. Each system has a condenser, evaporator, compressorand a thermal expansion device. The ambient air temperature is 30° C. atthe evaporator and the condenser inlets. Tests are performed for 2compressor speeds, 1000 and 2000 rpm, and for 3 vehicle speeds: 25, 30,and 36 km/h. The volumetric flow rate of air on the evaporator is 380m³/h.

The cooling capacity for the system with an IHX shows an increase of 4to 7% as compared to the system with no IHX. The COP also shows anincrease of 2.5 to 4% for the system with the IHX as compared to asystem with no IHX.

Example 2 Improvement in Performance with Internal Heat Exchanger

Cooling performance is calculated for HFC-134a and HFC-1234yf both withand without an IHX. The conditions used are as follows:

Condenser temperature 55° C. Evaporator temperature  5° C. Superheat(absolute) 15° C.

The data illustrating relative performance is shown in TABLE 5.

TABLE 5 Subcool, Capacity Compressor Test ° C. COP kJ/m³ work, kJ/kgHFC-134a, without 0 4.74 2250.86 29.6 IHX HFC-134a, with IHX 5.0 5.022381.34 29.6 HFC-134a, % 5.91 5.80 increase with IHX HFC-1234yf, without0 4.64 2172.43 24.37 IHX HFC-1234yf with IHX 5.8 5.00 2335.38 24.37HFC-1234yf, % 7.76 7.50 increase with IHX

The data above demonstrate an unexpected level of improvement in energyefficiency (COP) and cooling capacity for the fluoroolefin (HFC-1234yf)with the IHX, as compared to that gained by HFC-134a with the IHX. Inparticular, COP is increased by 7.67% and cooling capacity is increasedby 7.50%.

It should be noted that the subcool difference arises from thedifferences in molecular weight, liquid density and liquid heat capacityfor HFC-1234yf as compared to HFC-134a. Based on these parameters it isestimated that there would be a difference in subcool achieved with thedifferent compounds. When the HFC-134a subcool is set to 5° C., thecorresponding subcool for HFC-1234yf is calculated to be 5.8° C.

1. A method for exchanging heat in a vapor compression heat transfersystem having a working fluid circulating therethrough, comprising thesteps of: (a) circulating a working fluid comprising a fluoroolefin toan inlet of a first tube of an internal heat exchanger, through theinternal heat exchanger and to an outlet thereof; (b circulating theworking fluid from the outlet of the first tube of the internal heatexchanger to an inlet of an evaporator, through the evaporator toevaporate the working fluid and convert it into a gas, and through anoutlet of the evaporator; (c) circulating the working fluid from theoutlet of the evaporator to an inlet of a second tube of the internalheat exchanger to transfer heat from the liquid working fluid from thecondenser to the gaseous working fluid from the evaporator, through theinternal heat exchanger, and to an outlet of the second tube; (d)circulating the working fluid from the outlet of the second tube of theinternal heat exchanger to an inlet of a compressor, through thecompressor to compress the working fluid gas, and to an outlet of thecompressor; (e) circulating the working fluid from the outlet of thecompressor to an inlet of a condenser and through the condenser tocondense the compressed working fluid gas into a liquid, and to anoutlet of the condenser; (f) circulating the working fluid from theoutlet of the condenser to an inlet of the first tube of theintermediate heat exchanger to transfer heat from the liquid from thecondenser to the gas from the evaporator, and to an outlet of the secondtube; and (g) circulating the working fluid from the outlet of thesecond tube of the internal heat exchanger back to the evaporator. 2.The method of claim 1, where the fluoroolefin is at least one compoundselected from the group consisting of: (i) fluoroolefins of the formulaE- or Z—R¹CH═CHR², wherein R¹ and R² are, independently, C₁ to C₆perfluoroalkyl groups; (ii) cyclic fluoroolefins of the formulacyclo-[CX═CY(CZW)_(n)—], wherein X, Y, Z, and W, independently, are H orF, and n is an integer from 2 to 5; and (iii) fluoroolefins selectedfrom the group consisting of: 1,2,3,3,3-pentafluoro-1-propene(CHF═CFCF₃), 1,1,3,3,3-pentafluoro-1-propene (CF₂═CHCF₃),1,1,2,3,3-pentafluoro-1-propene (CF₂═CFCHF₂),1,2,3,3-tetrafluoro-1-propene (CHF═CFCHF₂),2,3,3,3-tetrafluoro-1-propene (CH₂═CFCF₃),1,3,3,3-tetrafluoro-1-propeneCHF═CHCF₃), 1,1,2,3-tetrafluoro-1-propene(CF₂═CFCH₂F), 1,1,3,3-tetrafluoro-1-propene (CF₂═CHCHF₂),1,2,3,3-tetrafluoro-1-propene (CHF═CFCHF₂), 3,3,3-trifluoro-1-propene(CH₂═CHCF₃), 2,3,3-trifluoro-1-propene (CHF₂CF═CH₂);1,1,2-trifluoro-1-propene (CH₃CF═CF₂); 1,2,3-trifluoro-1-propene(CH₂FCF═CF₂); 1,1,3-trifluoro-1-propene (CH₂FCH═CF₂);1,3,3-trifluoro-1-propene (CHF₂CH═CHF);1,1,1,2,3,4,4,4-octafluoro-2-butene (CF₃CF═CFCF₃);1,1,2,3,3,4,4,4-octafluoro-1-butene (CF₃CF₂CF═CF₂);1,1,1,2,4,4,4-heptafluoro-2-butene (CF₃CF═CHCF₃);1,2,3,3,4,4,4-heptafluoro-1-butene (CHF═CFCF₂CF₃);1,1,1,2,3,4,4-heptafluoro-2-butene (CHF₂CF═CFCF₃);1,3,3,3-tetrafluoro-2-(trifluoromethyl)-1-propene ((CF₃)₂C═CHF);1,1,3,3,4,4,4-heptafluoro-1-butene (CF₂═CHCF₂CF₃);1,1,2,3,4,4,4-heptafluoro-1-butene (CF₂═CFCHFCF₃);1,1,2,3,3,4,4-heptafluoro-1-butene (CF₂═CFCF₂CHF₂);2,3,3,4,4,4-hexafluoro-1-butene (CF₃CF₂CF═CH₂);1,3,3,4,4,4-hexafluoro-1-butene (CHF═CHCF₂CF₃);1,2,3,4,4,4-hexafluoro-1-butene (CHF═CFCHFCF₃);1,2,3,3,4,4-hexafluoro-1-butene (CHF═CFCF₂CHF₂);1,1,2,3,4,4-hexafluoro-2-butene (CHF₂CF═CFCHF₂);1,1,1,2,3,4-hexafluoro-2-butene (CH₂FCF═CFCF₃);1,1,1,2,4,4-hexafluoro-2-butene (CHF₂CH═CFCF₃);1,1,1,3,4,4-hexafluoro-2-butene (CF₃CH═CFCHF₂);1,1,2,3,3,4-hexafluoro-1-butene (CF₂═CFCF₂CH₂F);1,1,2,3,4,4-hexafluoro-1-butene (CF₂═CFCHFCHF₂);3,3,3-trifluoro-2-(trifluoromethyl)-1-propene (CH₂═C(CF₃)₂);1,1,1,2,4-pentafluoro-2-butene (CH₂FCH═CFCF₃);1,1,1,3,4-pentafluoro-2-butene (CF₃CH═CFCH₂F);3,3,4,4,4-pentafluoro-1-butene (CF₃CF₂CH═CH₂);1,1,1,4,4-pentafluoro-2-butene (CHF₂CH═CHCF₃);1,1,1,2,3-pentafluoro-2-butene (CH₃CF═CFCF₃);2,3,3,4,4-pentafluoro-1-butene (CH₂═CFCF₂CHF₂);1,1,2,4,4-pentafluoro-2-butene (CHF₂CF═CHCHF₂);1,1,2,3,3-pentafluoro-1-butene (CH₃CF₂CF═CF₂);1,1,2,3,4-pentafluoro-2-butene (CH₂FCF═CFCHF₂);1,1,3,3,3-pentafluoro-2-methyl-1-propene (CF₂═C(CF₃)(CH₃));2-(difluoromethyl)-3,3,3-trifluoro-1-propene (CH₂═C(CHF₂)(CF₃));2,3,4,4,4-pentafluoro-1-butene (CH₂═CFCHFCF₃);1,2,4,4,4-pentafluoro-1-butene (CHF═CFCH₂CF₃);1,3,4,4,4-pentafluoro-1-butene (CHF═CHCHFCF₃);1,3,3,4,4-pentafluoro-1-butene (CHF═CHCF₂CHF₂);1,2,3,4,4-pentafluoro-1-butene (CHF═CFCHFCHF₂);3,3,4,4-tetrafluoro-1-butene (CH₂═CHCF₂CHF₂);1,1-difluoro-2-(difluoromethyl)-1-propene (CF₂═C(CHF₂)(CH₃));1,3,3,3-tetrafluoro-2-methyl-1-propene (CHF═C(CF₃)(CH₃));3,3-difluoro-2-(difluoromethyl)-1-propene (CH₂═C(CHF₂)₂);1,1,1,2-tetrafluoro-2-butene (CF₃CF═CHCH₃); 1,1,1,3-tetrafluoro-2-butene(CH₃CF═CHCF₃); 1,1,1,2,3,4,4,5,5,5-decafluoro-2-pentene(CF₃CF═CFCF₂CF₃); 1,1,2,3,3,4,4,5,5,5-decafluoro-1-pentene(CF₂═CFCF₂CF₂CF₃); 1,1,1,4,4,4-hexafluoro-2-(trifluoromethyl)-2-butene((CF₃)₂C═CHCF₃); 1,1,1,2,4,4,5,5,5-nonafluoro-2-pentene(CF₃CF═CHCF₂CF₃); 1,1,1,3,4,4,5,5,5-nonafluoro-2-pentene(CF₃CH═CFCF₂CF₃); 1,2,3,3,4,4,5,5,5-nonafluoro-1-pentene(CHF═CFCF₂CF₂CF₃); 1,1,3,3,4,4,5,5,5-nonafluoro-1-pentene(CF₂═CHCF₂CF₂CF₃); 1,1,2,3,3,4,4,5,5-nonafluoro-1-pentene(CF₂═CFCF₂CF₂CHF₂); 1,1,2,3,4,4,5,5,5-nonafluoro-2-pentene(CHF₂CF═CFCF₂CF₃); 1,1,1,2,3,4,4,5,5-nonafluoro-2-pentene(CF₃CF═CFCF₂CHF₂); 1,1,1,2,3,4,5,5,5-nonafluoro-2-pentene(CF₃CF═CFCHFCF₃); 1,2,3,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene(CHF═CFCF(CF₃)₂); 1,1,2,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene(CF₂═CFCH(CF₃)₂); 1,1,1,4,4,4-hexafluoro-2-(trifluoromethyl)-2-butene(CF₃CH═C(CF₃)₂); 1,1,3,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene(CF₂═CHCF(CF₃)₂); 2,3,3,4,4,5,5,5-octafluoro-1-pentene(CH₂═CFCF₂CF₂CF₃); 1,2,3,3,4,4,5,5-octafluoro-1-pentene(CHF═CFCF₂CF₂CHF₂); 3,3,4,4,4-pentafluoro-2-(trifluoromethyl)-1-butene(CH₂═C(CF₃)CF₂CF₃); 1,1,4,4,4-pentafluoro-3-(trifluoromethyl)-1-butene(CF₂═CHCH(CF₃)₂); 1,3,4,4,4-pentafluoro-3-(trifluoromethyl)-1-butene(CHF═CHCF(CF₃)₂); 1,1,4,4,4-pentafluoro-2-(trifluoromethyl)-1-butene(CF₂═C(CF₃)CH₂CF₃); 3,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene((CF₃)₂CFCH═CH₂); 3,3,4,4,5,5,5-heptafluoro-1-pentene (CF₃CF₂CF₂CH═CH₂);2,3,3,4,4,5,5-heptafluoro-1-pentene (CH₂═CFCF₂CF₂CHF₂);1,1,3,3,5,5,5-heptafluoro-1-butene (CF₂═CHCF₂CH₂CF₃);1,1,1,2,4,4,4-heptafluoro-3-methyl-2-butene (CF₃CF═C(CF₃)(CH₃));2,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene (CH₂═CFCH(CF₃)₂);1,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene (CHF═CHCH(CF₃)₂);1,1,1,4-tetrafluoro-2-(trifluoromethyl)-2-butene (CH₂FCH═C(CF₃)₂);1,1,1,3-tetrafluoro-2-(trifluoromethyl)-2-butene (CH₃CF═C(CF₃)₂);1,1,1-trifluoro-2-(trifluoromethyl)-2-butene ((CF₃)₂C═CHCH₃);3,4,4,5,5,5-hexafluoro-2-pentene (CF₃CF₂CF═CHCH₃);1,1,1,4,4,4-hexafluoro-2-methyl-2-butene (CF₃C(CH₃)═CHCF₃);3,3,4,5,5,5-hexafluoro-1-pentene (CH₂═CHCF₂CHFCF₃);4,4,4-trifluoro-2-(trifluoromethyl)-1-butene (CH₂═C(CF₃)CH₂CF₃);1,1,2,3,3,4,4,5,5,6,6,6-dodecafluoro-1-hexene (CF₃(CF₂)₃CF═CF₂);1,1,1,2,2,3,4,5,5,6,6,6-dodecafluoro-3-hexene (CF₃CF₂CF═CFCF₂CF₃);1,1,1,4,4,4-hexafluoro-2,3-bis(trifluoromethyl)-2-butene((CF₃)₂C═C(CF₃)₂);1,1,1,2,3,4,5,5,5-nonafluoro-4-(trifluoromethyl)-2-pentene((CF₃)₂CFCF═CFCF₃);1,1,1,4,4,5,5,5-octafluoro-2-(trifluoromethyl)-2-pentene((CF₃)₂C═CHC₂F₅);1,1,1,3,4,5,5,5-octafluoro-4-(trifluoromethyl)-2-pentene((CF₃)₂CFCF═CHCF₃); 3,3,4,4,5,5,6,6,6-nonafluoro-1-hexene(CF₃CF₂CF₂CF₂CH═CH₂); 4,4,4-trifluoro-3,3-bis(trifluoromethyl)-1-butene(CH₂═CHC(CF₃)₃);1,1,1,4,4,4-hexafluoro-3-methyl-2-(trifluoromethyl)-2-butene((CF₃)₂C═C(CH₃)(CF₃));2,3,3,5,5,5-hexafluoro-4-(trifluoromethyl)-1-pentene(CH₂═CFCF₂CH(CF₃)₂); 1,1,1,2,4,4,5,5,5-nonafluoro-3-methyl-2-pentene(CF₃CF═C(CH₃)CF₂CF₃);1,1,1,5,5,5-hexafluoro-4-(trifluoromethyl)-2-pentene (CF₃CH═CHCH(CF₃)₂);3,4,4,5,5,6,6,6-octafluoro-2-hexene (CF₃CF₂CF₂CF═CHCH₃);3,3,4,4,5,5,6,6-octafluoro1-hexene (CH₂═CHCF₂CF₂CF₂CHF₂);1,1,1,4,4-pentafluoro-2-(trifluoromethyl)-2-pentene ((CF₃)₂C═CHCF₂CH₃);4,4,5,5,5-pentafluoro-2-(trifluoromethyl)-1-pentene (CH₂═C(CF₃)CH₂C₂F₅);3,3,4,4,5,5,5-heptafluoro-2-methyl-1-pentene (CF₃CF₂CF₂C(CH₃)═CH₂);4,4,5,5,6,6,6-heptafluoro-2-hexene (CF₃CF₂CF₂CH═CHCH₃);4,4,5,5,6,6,6-heptafluoro-1-hexene (CH₂═CHCH₂CF₂C₂F₅);1,1,1,2,2,3,4-heptafluoro-3-hexene (CF₃CF₂CF═CFC₂H₅);4,5,5,5-tetrafluoro-4-(trifluoromethyl)-1-pentene (CH₂═CHCH₂CF(CF₃)₂);1,1,1,2,5,5,5-heptafluoro-4-methyl-2-pentene (CF₃CF═CHCH(CF₃)(CH₃));1,1,1,3-tetrafluoro-2-(trifluoromethyl)-2-pentene ((CF₃)₂C═CFC₂H₅);1,1,1,2,3,4,4,5,5,6,6,7,7,7-tetradecafluoro-2-heptene(CF₃CF═CFCF₂CF₂C₂F₅);1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene(CF₃CF₂CF═CFCF₂C₂F₅); 1,1,1,3,4,4,5,5,6,6,7,7,7-tridecafluoro-2-heptene(CF₃CH═CFCF₂CF₂C₂F₅); 1,1,1,2,4,4,5,5,6,6,7,7,7-tridecafluoro-2-heptene(CF₃CF═CHCF₂CF₂C₂F₅); 1,1,1,2,2,4,5,5,6,6,7,7,7-tridecafluoro-3-heptene(CF₃CF₂CH═CFCF₂C₂F₅); 1,1,1,2,2,3,5,5,6,6,7,7,7-tridecafluoro-3-heptene(CF₃CF₂CF═CHCF₂C₂F₅); pentafluoroethyl trifluorovinyl ether(CF₂═CFOCF₂CF₃); and trifluoromethyl trifluorovinyl ether (CF₂═CFOCF₃).3. The method of claim 1, where the working fluid in the second tubeflows in a countercurrent direction to the direction of flow of theworking fluid in the first tube, thereby cooling the working fluid inthe first tube and heating the working fluid in the second tube.
 4. Themethod of claim 1, where the first tube has a larger diameter than thesecond tube, and the second tube is disposed concentrically in the firsttube, and a hot liquid in the first tube surrounds a cool gas in thesecond tube.
 5. The method of claim 1, wherein the condensing stepcomprises: (i) circulating the working fluid to a back row of a dual-rowcondenser, where the back row receives the working fluid at a firsttemperature; and (ii) circulating the working fluid to a front row ofthe dual-row condenser, where the front row receives the working fluidat a second temperature, where the second temperature is less than thefirst temperature, so that air which travels across the front row andthe back row is preheated, whereby the temperature of the air is greaterwhen it reaches the back row than when it reaches the front row.
 6. Themethod of claim 1, wherein the evaporating step comprises: (i) passingthe working fluid through an inlet of a dual-row evaporator having afirst row and a second row, (ii) circulating the working fluid in thefirst row in a direction perpendicular to the flow of fluid through theinlet of the evaporator, and (iii) circulating the working fluid in thesecond row in a direction generally counter to the direction of the flowof the working fluid through the inlet.
 7. The method of claim 1,wherein the working fluid further comprises at least one compoundselected from hydrofluorocarbons, fluoroethers, hydrocarbons, dimethylether (DME), carbon dioxide (CO₂), ammonia (NH₃), andiodotrifluoromethane (CF₃I).
 8. The method of claim 5, wherein theworking fluid further comprises at least one compound selected fromhydrofluorocarbons, fluoroethers, hydrocarbons, dimethyl ether (DME),carbon dioxide (CO₂), ammonia (NH₃), and iodotrifluoromethane (CF₃I). 9.The method of claim 6, wherein the working fluid further comprises atleast one compound selected from hydrofluorocarbons, fluoroethers,hydrocarbons, dimethyl ether (DME), carbon dioxide (CO₂), ammonia (NH₃),and iodotrifluoromethane (CF₃I).
 10. The method of claims 1, wherein thefluoroolefin comprises HFC-1234yf.
 11. The method of claims 5, whereinthe fluoroolefin comprises HFC-1234yf.
 12. The method of claims 6,wherein the fluoroolefin comprises HFC-1234yf.
 13. The method of claim10, wherein the coefficient of performance and the cooling capacity ofthe system is increased by at least 7.5% as compared to a system whichuses HFC-134a as the working fluid.
 14. The method of claim 11, whereinthe coefficient of performance and the cooling capacity of the system isincreased by at least 7.5% as compared to a system which uses HFC-134aas the working fluid.
 15. The method of claim 12, wherein thecoefficient of performance and the cooling capacity of the system isincreased by at least 7.5% as compared to a system which uses HFC-134aas the working fluid.
 16. A vapor compression heat transfer system forexchanging heat, comprising: (a) an evaporator having an inlet and anoutlet; (b) a compressor having an inlet and an outlet, wherein theinlet is connected to the outlet of the evaporator; (c) a dual-rowcondenser connected to the outlet of the compressor, the dual-rowcondenser having: (i) an inlet, (ii) a first row connected to the inlet,the first row comprising a first inlet manifold and a plurality ofchannels for allowing a working fluid at a first temperature to flowinto the manifold and then through the channels in at least onedirection and collect in a second outlet manifold, (iii) a second rowconnected to the first row, the second row comprising a plurality ofchannels for conducting a working fluid at a second temperature lessthan the refrigerant in the first row, (iv) conduit connecting the firstrow to the second row; and (d) an intermediate heat exchanger, having:(i) a first tube having an inlet connected to an exit of the condenserand an outlet, and (ii) a second tube having an inlet connected to anoutlet and an outlet connected to an inlet of the dual-row condenser;and wherein the inlet of the evaporator is connected to the outlet ofthe first tube of the intermediate heat exchanger.
 17. A vaporcompression heat transfer system for exchanging heat, comprising: (a) adual-row evaporator for evaporating a working fluid, the evaporatorhaving an inlet and an outlet; (b) a compressor having an inlet and anoutlet, wherein the inlet is connected to the outlet of the evaporator;(c) a condenser having an inlet and an outlet, wherein the inlet isconnected to the outlet of the compressor; and (d) an intermediate heatexchanger having: (i) a first tube having an inlet connected to an exitline of a condenser and an outlet connected to an inlet line of theevaporator; (ii) a second tube having an inlet connected to an outletline of the evaporator having an outlet.